0000000000204002
AUTHOR
Quentin Martinez
Common ragweed growth under different level of competition
Common ragweed (Ambrosia artemisiifolia L.) is colonizing various habitats. From mid-May to September 2012, the growth and development of different plants was monitored in four different habitats. Main development stages were observed and a final aerial biomass was measured. The number of ragweed plants surviving competition and management practices was lower in the plots with alfalfa than in the other plots. The number of ragweed plants reaching the male-flowering stage was significantly higher in the spontaneous vegetation and the “sown wildflowers”. Nevertheless, it was never observed a strong enough competition in any of the plots to avoid the flowering stage. We can extrapolate that in…
L'ambroisie se développerait au nord de l'Europe
EA EcolDur
Une envahissante dans le paysage : cas de l’ambroisie à feuilles d’armoise
L’ambroisie à feuilles d’armoise (Ambrosia artemisiifolia L.) est une espèce annuelle envahissante introduite en France à la fin du XIXe siècle. Plante rudérale, tolérante à de nombreux stress, l’ambroisie se développe essentiellement dans les habitats perturbés. Les principaux milieux occupés sont les parcelles agricoles, les bords de route et les zones perturbées par les activités anthropiques (jachères industrielles, zone de dépôt de matériaux …). Les berges de rivière constituent le seul habitat naturel dans lequel l’ambroisie peut former d’importantes populations. La semence d’ambroisie n’a pas de structure particulière favorisant son invasion. Trop lourde pour être dispersée par le ve…
Importance of seeds in the process of common ragweed invasion
International audience; Ambrosia artemisiifolia L. (common ragweed) was introduced into Europe at the end of the 1900s and is now present in several European countries. This annual invasive plant produces seeds that are highly polymorphic. Common ragweed can produce only a few thousand highly viable seeds. Many studies have focused on the seed stage. Greater seedling emergence for the seeds placed near the soil surface could explain the success of this species in open habitats, where the probability of deeper burial is low. Emergence percentage was found to decrease as burial depth increased from 2 to 8 cm, and no germination nor seedling emergence was observed for the seeds buried from 10-…
Impact of campaigns to control common ragweed on the pollen production in France
National audience; The dispersion of common ragweed (Ambrosia artemisiifolia L.) is anthropogenic, and because it is an invasive plant, a number of control procedures have been implemented whose effectiveness was measured. Measures on pollen emissions were compared between areas with different level of management. In addition to pollen traps of the French aerobiology network (RNSA), passive traps (SLT: SIGMA2 Like Trap) were positioned near controlled or non-controlled areas. Two areas were selected: - infested areas, in Rhône-Valley, 12 SLT were set up: 8 in Estrablin, with 2 in non-controlled areas and 6 in well-controlled areas; 4 near Valence, with one in non-controlled area and 3 in we…
How to explain the introduction of common ragweed into Europe during the XIXth century?
EA EcolDur (équipe CAPA) CT3; Various reasons can explain the success of A. artemisiifolia in France and in Europe :* introduction of plants from various sources (in space and time)* strong variability (morphology, size, etc.) * ecological plasticityDifferent situations across areas and countriesThe dominant habitats and the spread vector can differPotentially strong effects of the landscape (soil use)
Ragweed seed predation by invertebrates in cultivated area
National audience
Growth and development of Ambrosia artemisiifolia L. under different trophic conditions
Ambrosia artemisiifolia L. (common ragweed) is an annual weed regarded as an invasive plant in France. This species can be found in a large range of soil types with regard to texture, pH or nutrient contents. Furthermore, its tolerance to different forms of stress increases its spread potential. This work was undertaken to evaluate the development and growth of common ragweed under different trophic conditions in a common garden. Three cohorts of 15 plants per treatments were sown in spring 2013 and the effects of nitrogen and irrigation were compared on each sowing dates. During the first weeks, vegetative appearance is strongly linked with the sum of temperature. For the first cohort, the…
Ambrosia trifida L. in France: current distribution and ecological knowledge. Towards an eradication of the species?
National audience; Giant ragweed (Ambrosia trifida L.) is an annual plant belonging to Asteraceae, originating from North America. It was introduced in France in the early twentieth century. Originally described as a ruderal plant, Ambrosia trifida was recently reported in agricultural areas (maize and soybean) in the region Midi-Pyrénées. Beyond the potential public health issue, this species is a major invasive weed in North America, its native area. That is why a question arises about the future trend of the species in France. Can we expect a low ability of the species to adapt the French habitats and land-uses, with a low probability of naturalization? Viceversa, should we consider lead…
Mesure de l’efficacité de la lutte contre l’ambroisie : étude de faisabilité
Common ragweed (Ambrosia artemisiifolia L.) is known for its high allergenic pollens and by the difficulty to control this invasive plant which make it a problem for public health and is a harmfulness in rural areas. This first work aims to make a feasibility study to verify the proper functioning of selected traps and the correct implementation of specific procedures. It was decided to use passive traps SIGMA2 (SIGMA2 Like Trap ou SLT). Two geographical areas were selected, each with 4 traps: an infested area in Isère and a slightly infested area in Côte d'Or. SLT traps used can well collect pollen from local areas, the collected quantities vary in a corresponding manner according to the d…
Common ragweed national maps & public policies in France
Common ragweed (Ambrosia artemisiifolia L.) has been detected in France in the middle of the XIXth century. It has spread throughout the territory during the XXth century with a critical evolution. Public policies have not been able to contain this spread at the moment, and it is now difficult to find ways to tackle the invasion. Publication of national and regional maps seems to be an effective tool to draw up an overview of the situation and build management strategies. With a set of historical and modern data collected all over the French territory, and from many different stakeholders, we consider the progress of the species in time. The system of legislation applied locally is analyzed…
Création et rôle de l'Observatoire de l'ambroisie
L’envahissement du territoire français par l’ambroisie à feuilles d’armoise constitue à la fois une préoccupation de santé publique et un problème agricole important. Le ministère chargé de la Santé et l’Institut National de la Recherche Agronomique ont mis en place en juin 2011 l’« Observatoire de l’ambroisie » qui a pour mission principale la coordination des actions de lutte contre cette plante allergisante. Avec pour objectif de devenir un centre de ressources de références en matière d’ambroisie, l’observatoire contribuera à valoriser la connaissance sur la plante, notamment ses effets sur la santé, sur les actions durables de prévention, ainsi que sur les données scientifiques et les …